REFLECTOR: Odyssey Battery

Sat May 12 10:23:01 CDT 2007

Landing as soon as practical is probably a wise choice, but isn't it nice to 
be in the position to make the choice..  If I were flying to my home base, 
was say an hour out, sever clear, day VFR, I lost the alternator, and knew I 
had 2 or more hours of electrical reserve I might consider continuing on to 
my destination.  But then I would start to wonder if the problem was 
electrical or mechanical, what if an alternator bearing had failed and the 
stator was being ground to dust, what am I going to loose next would be on 
my mind.  In my case the alternator is driven by a belt shared with the 
water pump (auto engine conversion.)  Will continued mechanical failure 
affect the cooling system?  It doesn't matter how much fuel or electrons I 
have on board, I may end up with a forced landing.  In my case the prudent 
course would be land and check it out.  Installations are different and it 
is possible that a alternator failure in another AC may not have the same 
risks, so the decisions may be different.

In my case I am planning on reviewing possible failure modes and documenting 
the course of action prior to first flight.  This will be part of my 
emergency procedure section of the manual and onboard computer.  Better to 
think through problems on the ground.  These procedures will be incorporated 
into the onboard CPU Warning and Checklist systems, so options popup on the 
screen the same time as the warning.  The computer monitors the 50+ branch 
electrical circuits as well as all engine and flight data, so I should see a 
failure like an alternator long before I loose too many electrons.

Well enough rambling, should get back to building.

Joe

----- Original Message ----- 
From: "Tony Babb" <tonybabb at alejandra.net>
To: "'Velocity Aircraft Owners and Builders list'" <reflector at tvbf.org>
Sent: Saturday, May 12, 2007 8:32 AM
Subject: Re: REFLECTOR: Odyssey Battery

> This is a good discussion and one I've been pondering. I like Bob Nuckolls
> idea of having more electrons available in the battery than fuel in the
> tanks, it leaves you with the most options. When you're out of gas you're
> definitely going to have to land somewhere soon, but...I'm not sure I'd 
> make
> the conscious decision to carry on to my planned destination on battery
> power alone and possibly passing potential landing sites along the way, I
> think I'd look to land at the first available airport to find and fix
> whatever has broken. Am I being too conservative here? Just asking for a
> sanity check, no criticism intended for others who might make a different
> decision.
>
> Tony
>
> 62% done, 78% to go
> www.alejandra.net/velocity
>
> -----Original Message-----
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
> Behalf Of Hiroo Umeno
> Sent: Friday, May 11, 2007 2:50 PM
> To: Velocity Aircraft Owners and Builders list
> Subject: Re: REFLECTOR: Odyssey Battery
>
>
> Chuck, others,
>
> Thanks for the explanations.  I have dual 680 in the nose plus the
> afore-mentioned motorcycle battery backup.
>
> I probably should do a "run-down" test to see how long I have on each 
> stage
> to the total darkness.  It would be useful to know how long I have on each
> stage when the "unexpected" does happen.
>
> Hiroo
>
> -----Original Message-----
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
> Behalf Of Chuck Jensen
> Sent: Friday, May 11, 2007 2:30 PM
> To: Velocity Aircraft Owners and Builders list
> Subject: Re: REFLECTOR: Odyssey Battery
>
> Hiroo,
>
> Your not missing anything as far as the range of the Velo is concerned, 
> but
> its not always as simple as "land at the nearest IFR airport". Every year 
> or
> two, and some times more than once a year, the whole Atlantic Seaboard
> (thanks to spell check, I didn't post Seabroad) will be socked in with low
> lying fog that may be LIFR or worse.  3 or 4 years ago, there was this 
> very
> situation that trapped 3 planes that finally ran out of fuel looking for
> someplace they could land.
>
> Yes, you could head west over the mountains (Knoxville TN will be clear) 
> but
> it takes a brave heart to head for the mountains when the alternator is TU
> and the battery is headed the same direction.  A couple hundred miles to 
> the
> south, or north, you might be in the clear, but the pucker factor will
> certainly be high until you get there.  Now, if you know you have 3 or 4
> hours of battery and fuel to match, it becomes only a source of concern, 
> not
> of fright.  If I recall correctly, we fly our planes for pleasure, not to
> scare ourselves half to death.
>
> If I run the VFR capacity check and, with load shedding, I don't do better
> than 2 hours, the PC 680 is out and the PC 925 is "coming home to momma."
> With that said, I expect the 680 will give me more than two hours with 
> load
> shedding--strobe and nav lights are the first to go.  If things really get
> desparate, I might even consider killing the DVD and XM radio, but let's 
> not
> get hasty and panicky just yet.
>
> Chuck Jensen
>
>
>
>
> -----Original Message-----
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
> Behalf Of Hiroo Umeno
> Sent: Friday, May 11, 2007 3:55 PM
> To: Velocity Aircraft Owners and Builders list
> Subject: Re: REFLECTOR: Odyssey Battery
>
>
> I don't have IFR experience yet so I might be missing something but...
>
> Why do you need 2 hours?  Unless you are over open water or in the
> wilderness of Alaska, you are never too far from an airfield with an IFR
> approach, right?  So, if your "Low Voltage" light or "Alternater Failure"
> light comes on, then the process should be...
>
> 1.  Declare emergency to whomever you are currently talking to... 2. Get
> vectors to the nearest airfield with IFR approach... 3.  Get yourself 
> down.
>
> With an average speed of a Velocity at 160Kts or more, you should be able 
> to
> get down under most situation in 30 minutes or less, no?
>
> On my plane, I installed a secondary battery (motorcycle kind) that kicks 
> in
> when the mains go flat.  So the sequence of event on mine would look 
> like...
>
> 1.  Alternator failure light comes on. (Annunciator Panel) - Alternator is
> no longer supplying 13.5V or above to the bus. 2.  Low Voltage warning.
> (EFIS Alert) - Main battery getting low. 3.  Standby battery kicks in
> (Annunciator indicates Backup Battery) - Main bus is isolated. EFIS, panel
> lighting and Radios getting power 4.  Everything goes dark.
>
> I am hoping this is enough warning to "get me down in a hurry".
>
> The only thing about the way I did the electrical is that once the main 
> bus
> isolation kicks in, I will lose the ability to use any of the external
> lighting (NAV, Strobe, Landing Lights, etc).
>
> I will need to find a lighted field to land in.
>
> Hiroo
>
> -----Original Message-----
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
> Behalf Of Chuck Jensen
> Sent: Friday, May 11, 2007 12:11 PM
> To: Velocity Aircraft Owners and Builders list
> Subject: Re: REFLECTOR: Odyssey Battery
>
> Larry,
>
> Good advice all.  Fortunately, the GRT EFIS provides for alarming multiple
> voltage points, so an alternator going off line will put an alarm on the
> screen and I have a flashing red light for a separate alarm, though it
> doesn't put out an audio alarm to the head sets.  One would hope that 2
> hours is sufficient to escape IFR and with prompt load shedding, perhaps 3
> or more.  Still, juice is like money...more is always better.
>
> Chuck Jensen
>
> -----Original Message-----
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
> Behalf Of Laurence Coen
> Sent: Friday, May 11, 2007 2:57 PM
> To: Velocity Aircraft Owners and Builders list
> Subject: Re: REFLECTOR: Odyssey Battery
>
>
> Chuck,
>
> I use the Optima D34 (deep discharge version) like Pat.  I also did a
> battery rundown test to check the real world expectation as opposed to the
> theoretical.  During simulated night flight, two hours is all I got if I
>
> didn't shed load.  When the buss voltage hits 10V, your radios stop 
> working.
> In IFR this is not good.  The battery isn't really "dead" but you are a no
> radio flight.  The unfortunate truth about alternator failure is that it's
> noticed when the radios go dead. Too late!  The other thing that often
> happens is that the alternator partially fails and the battery slowly
> discharges with each flight.  This means when the alternator finally gives
> up the ghost your battery is already dead. What I'm trying to say is keep
> the volt and ammeter in your scan and understand what they're telling you.
> If you suspect a problem, shed load as much and as fast as you can. 
> whatever
> is gone isn't coming back.
>
> Larry Coen
> N136LC
>
> ----- Original Message -----
> From: "Chuck Jensen" <cjensen at dts9000.com>
> To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
> Sent: Wednesday, May 09, 2007 1:23 AM
> Subject: Re: REFLECTOR: Odyssey Battery
>
>
>> Keith,
>>
>> I concur with the two different missions for the battery, though I
>> understand the PC 680, in good condition, should be adequate for both
>> missions; namely cranking an IO 540 as well as provide escape time
>> from IFR electrical failure.  The IFR escape capacity of the battery
>> holds importance to me.  The PC 680, in good condition, seems to have
>> the 17 AH seems adequate to "get home" if the electrons stop birthing
>> and several parties report the 680 CA is amply to spin the IO 540, so
>> I'm going to give it a go.
>>
>> My current FLA battery is getting to the point that even after a good
>> charging flight, the next day it just barely makes the start, though
>> it always has.  Of course, when I install the PC 680, if I still have
>> the same problem, then I'll know to look elsewhere.  I believe this
>> process is known as being a "parts replacer" rather than a mechanic.
>> Of course, being a parts replacer makes me qualified to work in most
>> any automotive shop these days!
>>
>> And Pat, looking at your 38# monster battery, I'm thinking if your
>> alternator goes out, that you'll just have to remember to fix it after
>
>> two or three days of flying.  It's got enough juice to get you home,
>> back again and home again.
>>
>> Chuck Jensen
>>
>>
>> -----Original Message-----
>> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org]
>> On Behalf Of Keith Hallsten
>> Sent: Tuesday, May 08, 2007 9:52 PM
>> To: 'Velocity Aircraft Owners and Builders list'
>> Subject: Re: REFLECTOR: Odyssey Battery
>>
>>
>> Chuck,
>>
>> Sure - even a very small sealed lead-acid battery will crank the
>> engine... However, if you file IFR or fly at night and don't have a
>> back-up alternator you should consider establishing a minimum capacity
>
>> for the battery that will be sufficient to get you to your intended
>> destination without breaking a sweat.  That's an entirely different
>> question and will depend on your enroute electrical loads for, say,
>> night flight.  If you stick to day VFR, this is not a significant
>> consideration unless you have an electrically dependant engine (EFI,
>> electrical fuel pump only).
>>
>> Keith
>>
>>
>> -----Original Message-----
>> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org]
>> On Behalf Of Chuck Jensen
>> Sent: Tuesday, May 08, 2007 4:16 PM
>> To: Velocity Aircraft Owners and Builders list
>> Subject: REFLECTOR: Odessey Battery
>>
>> Is the Odessey PC 680 battery sufficient to crank the IO-540?
>>
>> Chuck Jensen
>>
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